#include <stdio.h>

int main(int argc, const char *argv[]) {
    int a = 10, b = 20;
    int * const p = &a;
    int **q = &p;
    //*p = 20;
    //**q = b;
    //*q = (int *)&b;    //此种方式，将二级指针q指向了b
    printf("%d\n", a);
    return 0;
}



